Improvement in artificial legs



F. V. NEUBERT, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN ARTIFICIAL LEGS.

Specification forming part of Letters Patent No. 45. M59, dated November22, 1861.

To all whom it may concern:

Be it known that I, F. IV. NEUBERT, of Pittsburg, in the county ofAllegheny and State ot' Pennsylvania, have invented a new and usefulImprovement in Artiiicial Legs; and I do hereby declare that thefollowing isa full, clear, and exact description of the construction andoperation of the same, reference being had to the accompanying drawings,making a part of this speciiication, and of which- Figures l to 3represent vertical sections through the leg, showing it in differentpositions, and Fig. 4, a transverse vertical section ofthe kneejoint.

In all these iigures the same letters of reference designate like parts.

A is the upper part of the leg5B, its lower part; @,thefoot. ais theknee-joint pin; b,the ankle-joint pin. The upper leg, A, is providedwith a bridge, c, to which are attached the cords d d and e c, whichextend and are fastened to the sole of the foot, the cord c c being madeelastic by a piece of i1idia-rubber,j, connecting the part c of the cordwith the part c.

j' is a projection or stop at the upper part of the leg, which, when theleg is straight, rests on a shoulder, g, ot' the lower part, B, as shownin Figs. l and 2, the contact being cushioned by a piece ot'india-rubber, h, fastened on the shoulder g.

The knee-joint is made in the usual way (excepting the position ofthefulcruni, which is farther back than in other constructions.)

'Its pin, a, passes through the eyes l l, riveted to the part A and theblock of wood m of the part B of the leg. The ankle-joint is made in asimilar manner, its pin b passing through the eyes l Z, riveted to thepart B and the block of wood n, fastened to the foot U.

The butt-end g g of the part B is made so as to enter, all around itscircumference, into the corresponding recess in the foot, incontradistinction to the usual mode in which the t'ore part, g, of thebutt-end enters into the foot, and the rear part, g', over the heel ofthe foot. 7c is a block of india-rubber fastened into the heel end ofthe recess in the foot, forming a cushion for the heel end g of the partB when the leg is in a vposition as indicated by red lines in Fig. l.

o is the toe joint, t, the toe-piece, made elastic by a piece of indiarubber, p, inserted between it and the fore part of the foot.

The nature of my improvement consists in the arrangement of the stop fand cushioned shoulder g, for the purpose of preventing the knee fromspringing or bending forward beyond a straight position, in combinationwith the elastic cord e c and cord el ci, for the purpose of throwingthe lower leg forward and giving a slight motion to the foot in steppingforward, as will be more fully shown .in the following description ofthe action of these parts, which, in their combination, produce all theproper steadiness, elasticity, and motions required to make an efficientartificial leg.

The Figs. l. to 3 exhibit the action, position, and motions of thedifferent parts constituting my improvement, when a person using the legis in the act of walking. Thus, in Fig. l the legisin a straight andperpendicular position, and the weight of the person rests on it. InFig. 2 it is in an inclined position before the knee is bent, when aportion ofthe weight of the person may still rest on it, and in Fig. 3the leg is shown when the knee (by the action of the stump of the natural leg) is bent. In this position no wei ght of thebody rests on theleg, and being thus relieved of any pressure on it, the action of theelastic cord c e will immediately throw the lower part, B,ot` the legforward, as indicated by red lines in Fig. 3, until it acquires again astraight but inclined position as indicated by red lines in Fig. l. Thebody in movin gforward will brin g the leg into the perpendicularposition again, as represented in Fig. l.

The strain of the elastic cord e e has a constant tendency ot' keepingthe leg straight.

'When the knee is bent,this corde c lays overthe block mot' theknee-joint, and, being extended thereby, its strain will be still moreincreased. 'Ihis cord e c', being attached to the foot in front oftheankle-joint fulcruin, will also constantly keep the fore part of thefoot raised up as far as the non-elastic cord d d (which is attached tothe foot, back of the ankle-joint fulcrum) will permit it. By bendingthe leg the cord cl d would get slack without the ac tion ot the elasticcord e c; but as soon as the cord cl d yields the cord ce forces thefore part ot' the foot up, and the cord cl cl is under strain again.Thus it will be seen that the fore part of the foot is raised to somedegree as long as th-e knee remains bent. In consequence hereof the forepart ofthe foot or toes is prevented from rubbing on the ground when theperson using` the ieg is steppin g forward.

rlihe inode of constructing` the butt-end y g of the part B so as toenter into the foot all around its periphery (as represented in thedrawings and described above) has the advantage that a shoe drawn overthe foot sits firmly and immovably, While in the ordinary constructions,in which the butt-end g of the lower leg is rnade to project over theheel of the foon. a friction is produced between said butt-end and theshoe, which prevents a free F. WV. NE BERT.

Witnesses:

J. DoNALDsoN, HENRY MOSER.

